Expression and significance of Fas and Bcl-2 proteins in human astrocytoma

Objective: To study the characteristics of Fas and Bcl-2 protein expression in human astrocytoma and their relations so as to provide a theoretical basis for prognostic evaluation and clinical therapy. Methods The expression of Fas and Bcl-2 proteins was investigated by SP immunohistochemical technique in 51 cases of astrocytoma specimens and 10 cases of normal brain tissues. All of the specimens were stained by HE, and the relationship between expression intensity of Fas/Bcl-2 proteins and malignancy grade (WHO grade I, II, III, and IV) of astrocytomas was analyzed. Results: The normal brain tissues did not show Fas protein immunostaining, and showed very weak Bcl-2 protein immunostaining in one case. By contrast, the astrocytomas showed Fas and Bcl-2 proteins immunostaining, and their positive rates and the intensity of expression were higher in high-grade astrocytomas than those in low-grade ones. There was also obvious difference between normal brain tissues and astrocytoma groups. In the Fas positive cases, Bcl-2 had a higher positive rate (68.6%) compared with that of Fas negative cases (43.8%). Conclusion Fas and Bcl-2 protein may be involved in tumoriogenesis and development of astrocytomas, and they might have a 0utual effect on each other. Our results suggest that the expression of Fas and Bcl-2 in astrocytoma have some clinical values in prognostic evaluation and immunotherapy.